As Calliostoma modestum:
Similar to C. hedleyi Pritchard & Gatliff in form and sculpture but has a different coloration and less dense spiral sculpture. Colour whitish with irregular grey spots. Body whorl very slightly convex with the periphery angled and with 7 nodulose spiral lirae. Base with about 10 weak, indistinctly nodulose spiral cords.

This species is somewhat similar to, and obviously congeneric with, Calthalotia arruense (Watson, 1880) from northern Australia. The Shark Bay specimens differ from typical C. arruense mainly in their shorter spire and more heavily developed columellar callus. Thiele (1930) remarked that his new species was similar to Calliostoma hedleyi and Cotton (1959) suggested that it was a probable variant of that species. C. hedleyi however, belongs to the subgenus Fautor (of Calliostoma) and is quite distinct from Thiele's species. Calthalotia Iredale, and Prothalotia Thiele, are probably very closely related groups but radular studies are required before their relationships can be more accurately assessed.

Height 18 mm; diameter 16 mm (from original description and these dimensions are those of the figured lectotype). Height 15 mm; diameter 15 mm (paralectotype).

Sharks (= Shark) Bay, north-western Australia ('a few specimens'). Only two specimens located.